Unbox is 3D platformer where the player is a cardboard box who must bounce and roll, through mountains and islands alike, to deliver themselves for the greater good of the Global Postal Service, or GPS. This can include racing against a clock, solving puzzles, and a lot of fun with physics, which often involves causing mayhem by knocking things over or blowing them up. The game also has a strong local multiplayer element, for full split-screen enjoyment, including a variety of different challenges.

To save themselves from bankruptcy, the GPS have somehow created living boxes that can deliver themselves to customers all over the world, to save on human staff. In Unbox, you will play as their latest creation, Newbie, and it is your job to complete the test islands, proving your worth as a sentient, self-delivering package.